Our first taste of spring thunderstorm activity will be here Tuesday evening and again Wednesday evening. This will not be anything major, but there will be a threat for wind and hail. As always, you can never rule out an isolated tornado this time of year, but that threat is very much on the low end.
The Storm Prediction Center recently started adding categories to describe the threat for severe thunderstorms and it's something I strongly disagree with. It goes back to the old rule, "less is more". At KATV, we will continue to use the the old threat scale: slight, moderate, and high. They have added marginal and enhanced. In my opinion, it's great for those who are weather geeks like me, but in terms of a public forecast, it just adds more confusion. If you feel differently, let me know in the poll to the right. Keep the old categorical scale or use the new categorical scale?
Here is their new scale...
More information on this categorical outlook: http://www.spc.noaa.gov/exper/dy1-3example/
Here is one we'll be using....
The following model maps are courtesy of WeatherBell Analytics
A slow moving front to the north will have waves of low pressure moving along it. The first one arrives this Tuesday evening and will mainly have an impact on NW Arkansas. A few storms will develop. As the low lifts away and instability decreases, the storms will decrease as they move south.
HiRes simulated radar shows the storms at around 9PM Tuesday.
Storms decrease later in the evening.
The Storm Prediction Center has placed NW Arkansas under a "slight risk" for severe weather late Tuesday.
The next wave of low pressure moves along the front late Wednesday. This will finally shove the front towards the south as it leaves and this will introduce much colder air.
It's going to be one of those wild weeks in Arkansas weather. We have a couple nice days, then the chance for some rough weather. I'm not expecting a major severe weather event, but a few strong and possibly severe storms will be possible.
The front bringing the storms will be the transition to a MUCH colder weather pattern. I hope you have not planted yet. The major long range models (GFS and EURO) differ on how cold it will get Friday and Saturday morning. This video goes over all of it for you.
It has been quite awhile since I updated the blog. Sorry for that. I have been working on a presentation I'm giving at the National Severe Storms and Doppler Radar Conference in Iowa. They asked me to present on the Mayflower/Vilonia tornado from last April 27th.
As I go through all the data and look at our coverage from that night, it really makes me think about things we need to work on. What really strikes me is the immediacy of social media and the reluctance I had that night to use photos at first.
We were getting pictures sent to us via twitter of the damage in Mayflower seconds after it hit. At that time, we knew we had a tornado on the ground, but we didn't know the size and the scope of the situation. I don't think anyone knew early that night it was a wedge tornado (a violent tornado that is wider than it is tall). I thought someone was sending me fake pictures on twitter. I could not believe what I was seeing. Just a few weeks prior to the tornado, we had a problem with fake flooding pictures floating around social media. These are the things we must deal with in a life and death situation. Social media is a fantastic resource for information, but it also allows some to post images that may not be real or were taken from many years ago from somewhere else.
This brings up a very, very important topic that must be addressed as we go into severe weather season. PLEASE KNOW WHO YOU ARE FOLLOWING ON SOCIAL MEDIA! There are so many people out there now who think they know what they are talking about, but in reality, they don't. I hate to have to say that, but it's true. They hide behind titles and they do not use their names. That should automatically raise suspicions. Some may know what they are talking about, but others do not. How do you know what kind of experience or education they have? Ask questions! For example, when we had that big winter weather event a couple weeks ago, prior to it, there were rumors floating around social media that it was going to be the Christmas 2012 storm all over again and many would lose electricity. I was asked this numerous times, but didn't respond. All I can do is stand by my forecast and the one made by Channel 7.
I think some of these pop up twitter accounts with no names attached to them are run by aspiring meteorologists. I can actually relate to them. I wanted to be a meteorologist since I was 6 years old. If twitter and facebook was available then, I would have been all over it. I do not want them to stop. They are passionate about the weather and that's a good thing. I just hope the ones behind these accounts are more open about who they are so no one is confused when we do encounter life and death situations.
Will this be an active severe weather season? That's a great question. Last year was very quiet with the exception of 1 storm and that's all it takes... ONE STORM! We are off to another slow start, but I hear from very experienced long range forecasters who are saying this will be a very active season starting in April and lasting into May. Their reasoning is based on science. One of those forecasters is Joe Bastardi with Weatherbell Analytics. His seasonal forecasting has been very, very good over the past few years.
We have above average sea surface temperatures in the Gulf of Mexico which could add more fuel to the atmosphere. Also, it is possible for the trough over the eastern and central United States to retrograde more to the west which would put this region in a more active pattern. Coming up soon here on the Arkansas Weather Blog, I will have more about this forecast and hopefully talk to Joe about his thoughts on this upcoming spring and summer.
As for my presentation, I can't promise this, but I'm going to try to stream it live here on the blog. So look for that next week. I will also do a special presentation here on the blog once I get back.
The numbers have verified and we have a winner for the winter contest. That person is STEVE ROBINSON with his guess of 24.6''.
Steven wins the grand prize which is a Davis home weather station, a download of the best radar app, RadarScope, and 4 tickets to the Golden Corral in North Little Rock.
Let's say, hypothetically, the contest included the snow in November through the present (March 6th). The combined snow at all 4 locations is 44.2'' and that's exactly what Ruben Keisler guessed. Sorry Ruben, the contest only went December 1 through February 28th, but it was a darn good guess!
12:20PM Wednesday Update... This video goes over timing and specifics using the highly regarded European model from Eurowx.com
It's really not a question of "if" we'll have a winter storm, it's "when". The freezing line will slowly drift from north to south today. Sleet and snow will fall across the north this morning with rain elsewhere. The rain should change to a mix of freezing rain and sleet across central sections around mid to late afternoon and southern Arkansas tonight. The sleet should change to snow after 9PM for most of central Arkansas.
The other factor we really need to talk about is the wind. I think gusts could easily exceed 30 mph later today and tonight. Most of the wintry weather will exit by sunrise Thursday and many kids will have yet another snow day. What about Friday? That all depends on what Mother Nature does to the roads Thursday afternoon. I think there will be some melting, but will it be enough? Temperatures Friday morning will drop into the teens and that will challenge record lows. The record low is 19 degrees set in 1899. That's a 116 year old record!!!!!!!!!! WOW! Any moisture on the roads will become ice once again so I think it's entirely possible some schools will be out Friday. That's not my call though.
The following maps are courtesy of EuroWx and Weatherbell Analytics.
Also below is the SCHOOL:CON index for Thursday
By noon Wednesday, all the frozen precipitation is across northern Arkansas. Green is rain, purple is freezing rain, pink is mix of freezing rain and sleet, and blue is snow. It will take some time for the subfreezing air to get around the Ozarks and funnel into the rest of the state on a northeast wind.
The European model shows a quick transition to ice and snow further south by 6PM. Notice how that area bulges into southeast Arkansas from the north. That's due to the NE winds down the east side of the mountains across north central Arkansas.
By midnight, the precipitation types continue to change as the depth of the cold air builds. We have freezing rain south, a mix just north of that, and snow for the northwest half of the state.
By 6AM, most of it has changed over to snow due to the arctic air building in strongly at all levels.
Between 6AM and Noon Thursday, the winter weather quickly moves away.
The HRRR run from early Wednesday shows this at 3PM. Notice the area of frozen precip moving south from NE Arkansas. That's due to the cold air funneling around the Ozarks and spilling south.
By 5PM, we are transitioning to wintry weather for much of the northern half of the state with the cold air deep enough across the far north for all snow. Southern Arkansas, that transition will happen later tonight.
SCHOOL:CON Index made Wednesday morning for Thursday.
POTENTIAL AMOUNTS. FORECAST MADE WEDNESDAY MORNING
3:30PM Tuesday Update... We finally have enough agreement with the models! It's not perfect, but our confidence level is above average at this point. School administrators will have a tough decision Wednesday morning for central Arkansas. I think it's possible to get a few hours in, then an early dismissal, but that's not my decision. School for much of the state Thursday does not look likely.
Northern and northeastern Arkansas will be hit the hardest with several inches of sleet and snow. I think amounts could reach 8'' and maybe more in spots. For central Arkansas, we're going with 2-5'' of sleet and snow with isolated higher amounts. I tend to side with the higher range of that scale, but not completely sold on that at this time. Southern Arkansas could see ice and up to 2'' of sleet and a little snow.
What about timing? I think we'll wake up to plain rain Wednesday morning, then the subfreezing air arrives in the metro around 1-4PM. We'll have freezing rain change to sleet, then we'll change to snow between 9 and midnight. The following weather maps are the GFS from Weatherbell Analytics.
Remember, green is rain, pink is freezing rain, orange is sleet, and blue is snow. I have drawn a black line to show you the 32 degree line according to this model. Everyone along and north of it is 32 degrees or colder.
For more information, scroll down. There's a video which goes over everything as well. I also have a SCHOOL:CON index for Wednesday and Thursday down there too.
Noon Wednesday
6PM Wednesday. The freezing line is well south of the metro. We feel the subfreezing air will arrive between 1-4PM
By midnight Thursday AM, everyone is below freezing
Early Thursday morning, the precipitation is decreasing from NW to SE
By late Thursday morning, it should be gone
This is our forecast at this point, but is still subject to change. As I stated above, I would not doubt isolated higher amounts north. I feel it's possible we'll be in the upper portion of the 2-5'' scale, but not completely sold yet.
We are within 1-2 days of this and there are still model uncertainties in regards to precipitation type and the duration of each. What we do feel confident in at this point is the timing. Northern Arkansas will first be affected by this Wednesday morning, then it will spread southward into central Arkansas during Wednesday afternoon, then southern Arkansas late in the day and Wednesday night.
All types of winter precipitation will be likely creating what I call an "Arkansas Slushie". Once this decreases, we'll have a chance to challenge near record low temperatures. With the higher sun angle in March, roads should clear up rapidly Thursday afternoon and again Friday afternoon. Tired of all this? I think we'll really begin to warm up next week. Let's just get through this!
The video below is loaded with information and specifics. Below the video is the SCHOOL:CON index for Wednesday and Thursday. I really think the main impact for school closings Wednesday will be northern Arkansas, then other ares Thursday. Hope the kids like school in June.
Thanks for making the Arkansas Weather Blog your choice for information.
SCHOOL:CON INDEX FOR WEDNESDAY. LIKE I SAID ABOVE, CENTRAL AND SOUTHERN ARKANSAS MIGHT BE ABLE TO GET A FULL DAY IN DUE TO THE SUBFREEZING AIR ARRIVING LATER IN THE DAY. THIS IS STILL SUBJECT TO CHANGE
1PM Monday Update... for a more detailed discussion, please watch the video below.
There are still uncertainties regarding the winter storm Wednesday. When will it cool to 32 degrees or colder is a one of those concerns. Also, precip. type is uncertain. There should be a transition from rain to freezing rain to sleet to snow at many locations. How long you have a certain type is quite debatable. I'm going to show you three models below and how different they are with respect to the 32 degree line. Also below is the first SCHOOL:CON index issued. I'll update that again Tuesday.
The GFS is quickest with bringing subfreezing air south. At noon Wednesday, everyone along and north of that white line is 32 degree or colder.
The European model at noon Wednesday has that line further north and slower moving towards the south.
At 5PM, the NAM still has much of the state ABOVE freezing. So you see the uncertainties here! At this time, I'm leaning towards the middle of the road approach, Euro.
The first SCHOOL:CON index shows the highest chance for no school Wednesday will be north and less likely south due to the uncertainties of the freezing line. Is it possible to get school in across south Arkansas, then have the winter weather later in the afternoon? sure! I will update this Tuesday.
It's looking more and more likely another winter storm will affect the state. The worst of this may be over northern, central, and eastern Arkansas, but the details can still change. All forms of precipitation will be possible starting Wednesday morning. We'll go from plain rain, to freezing rain, then to sleet and snow.
Having a snow storm in March is NOT unusual, especially early March. IF this storm comes together, roads may be rotten Wednesday, but should improve by Thursday afternoon due to the higher sun angle in March. You can have temperatures in the upper 20s and the roads will melt off. So at this time, I think travel will be difficult, but not for days.
One other aspect to the end of the week, we'll have the potential to break record low temperatures IF there is snow and ice on the ground. Those records are in the mid and upper teens and we could challenge that.
This video is loaded with specifics and my thoughts about this possible winter storm. Thanks for coming to the Arkansas Weather Blog for your information.
We just can't shake off winter even though we are officially in meteorological spring now. This video is a very in-depth look at the models and differences that exist for the Wednesday event. Also, I discuss the potential winner in the Arkansas Weather Blog winter contest.
